The name comes from Jogaila (Jagiełło), the first Grand Duke of Lithuania to become King of Poland. In Polish, the dynasty is known as Jagiellonowie and the patronymic form: Jagiellończyk; in Lithuanian it is called Jogailaičiai, in BelarusianЯґайлавічы (Jagajłavičy), in HungarianJagelló, and in CzechJagellonci, as well as Jagello or Jagellon in Latin.

After Sigismund II Augustus, the dynasty underwent further changes. Sigismund II's heirs were his sisters Anna Jagiellon and Catherine Jagiellon. The latter had married Duke John of Finland, who thereby from 1569 became King John III of Sweden, and they had a son, Sigismund III Vasa; as a result, the Polish branch of the Jagiellonians merged with the House of Vasa, which ruled Poland from 1587 until 1668. During the interval, among others, Stephen Báthory, the husband of the childless Anna, reigned.

At one point, the Jagiellonians established dynastic control also over the kingdoms of Bohemia and Hungary (from 1490 onwards), with Vladislaus Jagiello whom several history books call Vladisla(u)s II. After being elected and crowned King of Hungary, Vladislaus moved his court to Hungary from where he ruled both countries and his children were born and raised. By Louis' sudden death in Battle of Mohács in 1526, that royal line was extinguished in male line.

^Jadwiga was crowned King of Poland — Hedvig Rex Poloniæ, not Hedvig Regina Poloniæ. Polish law had no provision for a female ruler (queen regnant), but did not specify that the King had to be a male. The masculine gender of her title was also meant to emphasize that she was monarch in her own right, not a queen consort.